Spring relief mechanism for jaw type crushers



March 12, 19,57 s. w. TRAYLOR, JR

SPRING RELIEF MECHANISM FOR JAW TYPE CRUSHERS 2. 1 2 m .T- 9 ll e h |l s lllllll E T 2 l l l l I I l l l i Il \\\II\\ H1511. w f 2 v M March 12, 1957 s. w. TRAYLOR, JR 2,784,916

SPRING RELIEF MECHANISM FOR Aw TYPE cRUsHERs Filed Aug. 24, 1953 2 Sheets-Sheet 2 United States Patent O SPRING RELIEF MECHANISM FOR JAW TYPE CRUSHERS The present invention relates to jaw-type crushers and more particularly to spring relief mechanisms for relieving the strain on the crushing jaws and associated mechanism when an uncrushable object such as tramp iron lodges itself between the crusher jaws.

It is desirable to provide means for relieving the pressure on the crusher jaw when an uncrushable object is trapped between the fixed and swing jaws of a jaw-type crusher. If the pressure is not relieved, the object trapped in the jaw cavity tends to distort the jaw and the associated mechanism and may even become jammed thus rendering it inoperative. When this occurs, it is necessary to shut down the crusher, remove the uncrushable object, and replace the damaged parts.

It has been impractical in conventional apparatus to provide a spring bias to relieve the fixed or movable jaw of the crusher because of the substantial thrust imparted to the movable jaw during normal operation. To provide a direct spring bias on the jaw would require springs of substantial size which would disproportionately increase the cost of the crusher. It has been `attempted to provide emergency relief for the jaw by providing the toggle mechanism for actuating the swing jaw with toggle members which fracture or rupture when the load on the jaw exceeds a predetermined maximum value. This method of relief is not entirely satisfactory since the fracturable toggle members cannot be made precisely uniform, and it is impractical to adjust the desired maximum load. In addition, the crusher must be shut down to replace the fractured toggle members whenever an uncrushable object lodges itself between the jaws.

With the foregoing in mind, a primary object of the present invention is to provide a novel relief mechanism for jaw-type crushers which is readily `adjustable to predetermine the maximum load -at which the mechanism relieves the pressure on the swing jaw.

Another object of the invention is to provide a relief mechanism which operates repeatedly without replacement ofthe parts thereof.

A further object of the present invention is to provide a novel relief mechanism for jaw-type crushers which s of simple construction and is entirely eicient and effective in operation and use.

These and other objects of the invention and the various features and details of the construction and operation thereof are more fully set forth hereinafter with reference to the accompanying drawings in which:

Fig. l is a plan view of a Blake-type jaw crusher embodying a spring relief mechanism made in accordance with the present invention;

Fig. 2 is a sectional View on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged sectional View similar to Fig. 2 showing the operation of the spring relief mechanism;

Fig. 4 is a detached perspective view of an element of the mechanism illustrated in Figs. 1 to 3; and

Fig. 5 is a fragmentary sectional view similar to Fig. 2 disclosing a modified form of spring relief mechanism made in accordance with the present invention.

For `the purposes of this disclosure, the invention is shown and described as applied to jaw crushers embodying the novel toggle mechanism disclosed in my copending application, Serial Number 371,992, led August 3, 1953, now Patent No. 2,751,159, .but it is to be understood that the invention may be applied to jaw crushers embodying the prior conventional toggle mechanism.

Referring now to the drawings `and more particularly to the embodiment illustrated in Figs. l to 4 thereof, the crusher comprises a frame having a fixed jaw plate 11 rigidly secured adjacent one end thereof, a swing jaw 12 mounted on a shaft 13 fixed in the frame 10, a toggle mechanism 14 disposed between the swing jaw 12 and the opposite end of the frame 10 and a pitman 15 engaging the toggle mechanism `and mounted for vertical reciprocation by a driven eccentric shaft 16. In the present instance, the toggle mechanism comprises a plurality of sets of toggle members 20 and 21 respectively. One set 20 is compressed between a distributor 22 and the swing jaw 12 and the other set 21 is compressed between the frame 10 and the distributor 22. Thus, when the eccentric shaft 16 is driven, the pitman 15 reciprocates vertically to actuate the toggle mechanism 144 to effect swinging movement of the swing jaw 12 on the shaft 13 toward and away from the fixed jaw 11.

In accordance with the invention, when an uncrushable object such as, for example, tramp iron, is lodged between the fixed jaw 11 and the swing 12, a spring relief mechanism operates to relieve the pressure exerted on the swing jaw by the toggle mechanism. To this end, in the present instance, the one set of toggle members 20 engages against the end surface of the movable toggle block 25 which in turn is seated at its other end against the swing jaw 12. As shown in Fig. 2, a toggle member 20 and the toggle block 25 are in end-abutting relation, but it should be noted that these members are not in precise longitudinal alignment. To illustrate this, the longitudinal center lines of the toggle member 2l) and the toggle block 25 are indicated respectively at x and y. As is apparent, there is a small angle, inthe present embodiment, approximately 2 degrees, between the center lines x and y.

i The toggle block 25 engages against a limit plate 26 formed integrally with the swing jaw 12 to prevent the block 25 and the toggle member 20 from passing into axial alignment. The block 25 is resiliently biased against the limit plate Z6 by means of a bolt 27 spring-biased upwardly by a spring bias 28 and associated locking nuts 29. By reason of this construction, the toggle block is free to move angularly away from the limit plate 26 when the downward component of the force exerted thereon by the swing jaw 12 exceeds the spring force of the spring 28, and in the case of the small 2 degree angle between the center lines x and y in the illustrated embodiment of the invention, the force of the swing jaw on the toggle block required to overcome the upward bias of the spring 28 is approximately 28.5 times the compressive spring force.

In operation of the crusher, as the pitman reciprocates vertically, the toggle member moves angularly relative to the normal stationary toggle block 25. However, as the toggle member moves, it is prevented from coming into axial alignment with the toggle block because of the position of the limit plate 26. The angularity between the toggle member and the toggle block increases during the upward travel of the pitman to reduce the force required to displace the toggle block 25 away from the limit plate 26. This does not adversely affect the pressure relief mechanism because in the normal operation of the crusher the greatest strain on the jaw occurs when the toggle member and the toggle block are closest to axial alignment, i. e., when the jaws are closest together. It is noted that the toggle block Patented Mar. 12, 1957.`

25 is provided with enlarged slots 29 for receiving the bolts Z7 which afford ample angular movement of the toggle block on its extremity where it engages in the swing jaw 12. This is clearly illustrated in Fig. 3.

A Fig. 5 illustrates a Blake-type crusher wherein the spring relief mechanism is applied to the other set of toggle members which span between the pitman and the fname. In this figure, the pitman is lindicated at 31, the swing. jaw at 32, the frame at 33, and the two sets of toggle members at 34 and 35 respectively. In accordance with the conventional practice, the longitudinal position of the toggle member is adjustable by means of adjusting blocks 36 and 37 respectively.

In this form of the invention, a toggle block 38 is in endwise abutting relation with the toggle member 35 and the inner adjusting block 36. As in the previously described' embodiment, the toggle block 38 and the toggle member 35, are not in'precise longitudinal alignment but are disposed at a small angle relative to one another as indicated by their center lines xl vand yl. To prevent the toggle member and block from coming into axial alignment, 1a limit plate 39 xed on the frame 33, engages against the upper surface of the toggle block 38. The toggle block is biased into engagement with the limit plate 39 by means of a spring 4t) seating at its upper end against the toggle block 3S and at its lower end, against a depending portion 41 of the frame 33. In this manner, the toggle block is normally positioned against the limit plate 39. As in the previously described embodiment, the angle between the center lines xl and yl is preferably on the order of 2 degrees when the pitman is in its lower limit position. Thus, the longitudinal force on the toggle member required to displace the toggle block 38 downwardly against the bias of the spring et), is approximately 28.5 times the spring force of the spring 40.

in each of the above-described embodiments of the invention, strain on the swing jaw caused by the lodging of an uncrushable object in the Crusher cavity is substantially eliminated by afording angular displacement of a toggle block relative to a toggle member. The normal relative position of the toggle block and the toggle member is limited to less than 180 degrees so that the members do not lock with one another. A bias is applied to the toggle block in a direction approximately normal to the longitudinal center lines of the toggle member and toggle block so that the force of the bias is greatly multiplied. The illustrated forms of the invention employ a spring bias which is provided with adjusting means to regulate the minimum force required to displace the toggle block away from the limit means. Thus, the invention affords a simple and inexpensive pressure relief mechanism which is readily adjustable to meet the requirements of the trade.

While particular embodiments of the invention have been herein illustrated and described, it is not intended to limit the invention to such disclosures, and changes and modications may be made therein and thereto within the scope of the following claims.

I claim:

l. In a jaw-type crusher having a frame, a jaw fixed adjacent one end of said frame and a swing jaw mounted for swinging movement toward and away from said fixed jaw, a toggle mechanism disposed between said swing jaw and the frame for effecting swinging movement of the swing jaw comprising a pitman, means mounting said pitman for vertical reciprocation, at least one toggle member mounted in-endwise compression between said swing jaw and said pitman, at least one toggle member mounted in endwise compression between the opposite end of the frame and the pitman, a toggle block inter posed in endwise compression between the lirst of said toggle members and the swing jaw, said toggle member and toggle block being in end-abutting relation for relative angular movement, means to limit the angular movement of said abutted members in Vone direction to a assente l less-than-lSO degrees relationship, and means biasing said abutted members against said limit means with a predetermined force, said abutted members moving vangularly away from said limit means when the endwise forces thereon exceed a given value.

2. In a jaw-type crusher having a frame, a jaw xed adjacent one end of saidframe and a swing jaw mounted for swinging movement toward and away from said fixed jaw, a toggle mechanism disposed between said swing jaw and the frame for effecting swinging movement of the swing jaw comprising a pitman, means mounting said pitman for vertical reciprocation, at least one toggle member mounted in endwise compression between said swing jaw and said pitman, at least one toggle member mounted in endwise compression between the opposite end of the frame and the pitman, a toggle block interposed in endwise compression between the lirst of said toggle members and the swing jaw, said toggle member and toggle block being in end-abutting relation for relative angular movement, a plate mounted on said swing jaw and engaging the toggle block to limit the angular movement of said abutted members in one direction to a less-than-l80 degrees relationship, and means biasing said abutted members against said limit plate with a predetermined force, said abutted members moving angularly away from said limit plate when the endwise forces thereon exceed a given value.

3. in a jaw-type Crusher having a frame, a jaw xed adjacent one end of said frame and a swing jaw mounted for swinging movement toward and away from said iixed jaw, a toggle mechanism disposed between said swing jaw and the frame for effecting swinging movement of the swing jaw comprisingla pitman, means mounting said pitman for vertical reciprocation, at least one toggle member mounted in endwise compression between said swing jaw and said pitman, at least one toggle member mounted in endwise compression between the opposite end of the frame and the pitman, a toggle block interposed in endwise compression between the second of said toggle members and the opposite end of the frame, said toggle member and toggle block being in end-abutting relation for relative angular movement, means to limit the angular movement of said abutted members in one direction to a less-than-l80 degrees relationship, and means biasing said abutted members against said limit means with a predetermined force, said abutted members moving angularly away from said limit means when the endwise forces thereon exceed a given value.

4. in a jaw-type Crusher having a frame, a jaw xed adjacent one end of said frame and a swing jaw mounted for swinging movement toward and away from said iixed jaw, a toggle mechanism disposed between said swing jaw and the frame for effecting swinging movement of the swing jaw comprising a pitman, means mounting said pitman for vertical reciprocation, at least one toggle member mounted in endwise compression between said swing jaw and said pitman, at least one toggle member mounted in endwise compression between the opposite end of the frame and the pitman in endwise compression therebetween, a toggle block interposed in endwise compression between the second of said toggle members and the opposite end of the frame, said toggle member and toggle block being in end-abutting relation for relative angular movement, a plate mounted on theframe and engaging said toggle block to limit the angular movement of said abutted members in one direction to a less-than-lSO degrecs relationship, and means biasing said abutted members against said limit plate with a predetermined force, said abutted members moving angularly away from said limit plate when the endwise forces thereon exceed a given value.

5. In a jaw-type Crusher having a frame, a jaw fixed adjacent one end of said frame and a swing jaw mounted for swinging movement toward and away from said xed jaw, a toggle mechanism disposed between said swing jaw and the frame for effecting swinging movement of the swing jaw comprising a pitman, means mounting said pitman for vertical reeiprocation, toggle members mounted in endwise compression between said pitman and said swing jaw and the opposite end of the frame respectively, a toggle block engaging the end of one of said toggles remote from said pitman and abutting said toggle in end- Wise compression, said toggle member and toggle block being mounted for relative angular movement, means engaging said toggle block to limit the angular movement of said abutted members in one direction to a lessthan-180 degrees relationship, and means biasing said toggle block against said limit means with a predetermined force, said abutted members moving angularly away from said limit means when the endwise forces thereon exceed a given value.

References Cited in the file of this patent UNITED STATES PATENTS 1,101,480 Warsen June 23, 1914 1,130,864 Warsen Mar. 9, 1915 2,094,465 Peterson Sept. 28, 1937 FOREIGN PATENTS 267,339 Germany Nov. 14, 1913 

